In September 2014, a 40th Anniversary edition of the book was released, featuring all the original illustrations redrawn in colour by the author, Jill Murphy.

Plot

The novel begins with Mildred Hubble and her best friend Maud talking about the upcoming ceremony where all of the first-years will be given their own black cats which they will teach to ride on their broomsticks with them. Miss Hardbroom (their extremely strict form-mistress and also the deputy headmistress) catches them and sends Maud back to her own room. When receiving the black kittens, Mildred is the last in the queue and receives, not a sleek, black kitten like the other girls, but a tabby cat (whom she names Tabby). When trying to get Tabby to sit on her broomstick, he keeps falling off without even trying to cling on.

After losing patience, Mildred puts Tabby in her satchel but Miss Hardbroom disapproves and Mildred has to stop. After seeing the confrontation between Mildred and Miss Hardbroom, a rather smug witch called Ethel Hallow (for whom everything goes right) teases Mildred about it. After warning her about a frog-transformation, Ethel goads Mildred into turning her into a frog but Mildred loses her temper and accidentally turns her into a pig instead. Mildred quickly takes the Ethel-pig to the library where she restores her to her human form.

In the next chapter, Mildred and Maud are making a laughing potion. They add pondweed mistaking it for one of the ingredients but make an invisibility potion instead. In the next chapter, the girls are practicing for a broomstick display for Halloween. During this, Miss Hardbroom notices Mildred's broken broom (she broke it on her second day at the academy after falling over a fence and crashing into some dustbins). Ethel lends Mildred her spare broom but puts a jinx on the broom to get even with Mildred for the pig transformation. During the Halloween festival, Mildred's lent broom starts rocking and jerking dangerously.

Havoc erupts as this bucking bronco-like broomstick causes all of the girls to fall from their

Mildred with the Snails

broomsticks. Ethel is the only one to land safely on two feet. Miss Cackle, Miss Hardbroom, and the chief-magician angrily accuse Mildred of ruining the display and Mildred is set for an interview with Miss Cackle and Miss Hardbroom the next morning. Mildred, fearing expulsion when the interview is over, decides to run away with Tabby. When walking through the forests surrounding the academy, Mildred hears voices through the trees and comes across a coven of witches headed by a witch who looks like Miss Cackle whom the coven call Agatha Cackle.

After hearing their plot to turn every teacher and pupil in the academy into frogs, Mildred, in terror, turns Agatha and the rest of the coven into snails. Mildred packs the snails in the cardboard boxes that were meant for the frog-teachers and frog-pupils and takes them back to the academy. Miss Cackle reveals that the Agatha Mildred saw is actually Miss Cackle's identical twin sister who is the polar opposite of her. They turn Agatha and the rest of the coven back into humans and Mildred's interview is canceled. Mildred is commended as a herione to the rest of the academy.

Covers

Original Cover

TV cover (UK)

TV cover (US)

Cover Illustrated by Jill Murphy

New Cover

40th Anniversary colour edition

2017 TV tie-in cover

Alternative Cover

Alternative Cover

Omnibus of The Worst Witch, The Worst Witch Strikes Again, and A Bad Spell for the Worst Witch

Omnibus of The Worst Witch and The Worst Witch Strikes Again

Omnibus of The Worst Witch, The Worst Witch Strikes Again, and A Bad Spell for the Worst Witch

Trivia

Agatha Cackle, Miss Cackle's rebel-ish identical twin sister, leader of the coven and the main antagonist of the novel, would later reappear in the fifth novel The Worst Witch Saves The Day disguised as a new teacher, Miss Granite.

The invisibility potion that the girls make in chapter four is the same potion the frog-Mildred used to turn invisible in A Bad Spell For The Worst Witch.